Mascara brush



1.1 is a front view;

1.2 is a top view;

1.3 is a side perspective view;

1.4 is a side view; and

1.5 is a bottom view.

In the drawings, the broken lines are for the purpose of illustrating portions of the mascara brush that forms no part of the claimed design. 

CLAIM The ornamental design for a mascara brush, as shown and described. 